The decomposition of methane in the glow discharge at liquid‐air temperature has been investigated under different experimental conditions. Contrary to the earlier conclusion of Brewer and Kueck that the reaction products are only hydrogen and ethylene, they are invariably found to be hydrogen, a polymer of composition (CH2)n, and ethane, ethylene, and acetylene, the last three resulting presumably from the mutual interaction of the primary active species CH4+, CH3+, CH2+, CH+ formed from methane. In the absence of hydrogen, ethane predominates; in its presence, ethylene and acetylene proportions increase due, it is suggested, to the dehydrogenating action of atomic hydrogen. In the negative glow, the rate of methane decomposition is directly proportional to the current, and the electronic efficiency, i.e., the number of methane molecules decomposed per electronic charge, is ∼10 both for alternating and direct current. In the positive column, the rate is directly proportional to current only if pressure and field strength are constant; with constant current, the rate increases with pressure and field strength but in a manner which does not lend itself at present to a quantitative expression; the electronic efficiency is ∼0.2 for alternating and ∼0.6 for direct current. The results lead to the conclusion that a 60‐cycle alternating current discharge approximates closely to that with direct current. These may be explained by considerations of the electrical energies involved. No marked difference in reaction rate or products is observed by substituting iron for aluminum electrodes, or by variation in current density. A certain chemical activity might be attributed to the Faraday dark space.

An investigation has been made of the polymerization of ethylene photosensitized by zinc, both resonance lines, 2139A and 3076A, being used. With λ3076 the rate of the reaction is very small, and it is concluded that this is probably due to inefficient quenching. With λ2139 a rapid polymerization occurs. The products of the reaction are propylene, butene, and small amounts of higher hydrocarbons. Acetylene formation is negligible. The rate of polymerization increases rapidly with increasing ethylene pressure. While there is some doubt about the mechanism, the most plausible suggestion seems to be that the initial step isand that this is followed by an atom and free radical sensitized polymerization of ethylene.

From the known structure of the diamond the total surfaceenergy of the crystal has been calculated in terms of the energy of the carbon‐carbon bond, and is found to be: 1.50×10−9EB erg cm−2 for the 111 face, and 2.10×10−9EB erg cm−2 for the 100 face, where EB is the energy in ergs per bond. If the bondenergy is assumed to be 90 kcal. mole−1 the values become 5650 erg cm−2 for the 111 face, and 9820 erg cm−2 for the 100 face. The corresponding free surfaceenergies are found to be: 111 face at 25°=5400 erg cm−2 100 face at 25°=9400 erg cm−2. One uncertain feature in the calculation is that involved in the calculation of the decrease in energy caused by the long range binding of the valence bonds in the surfaces. In the 111 face the bonds are 2.517A apart, and are perpendicular to the surface. Thus the bond directions are parallel, while inside the diamond the carbon‐carbon distance is only 1.54A, and the bonds meet head on. While in the 111 face there is only one bond per carbon atom, in the 100 face there are two bonds per atom. In the 111 face there are 1.825×1015bonds per sq. cm−2, with an area of 5.48A2 each, while in the 100 face the corresponding values are 3.158×1015bonds per cm2 and 3.167A2 per bond. It is concluded that in the 111 face the interaction energy of the type described above is less than one percent and is negligible. Even in the 100 face the interaction should be small. No account was taken of any adjustment of the energy of the unsevered bonds in the surface region. This should cause a greater decrease of energy than the long range binding of the severed bonds. Thus the values of the surfaceenergy calculated in this paper should be considered as maximum values.

The third law, or law of limits as T→0°K, is expressed as: ``for any real phaseand for any spontaneous isothermal process,The equality sign applies to reversible processes and the inequality sign to irreversible processes. The n's represent composition variables, the x's (or T and the y's) a suitable set of state variables, and the v's the number of moles of the components entering into the reaction (positive for products, negative for reactants). Alternative statements of the third law are given and derived from the above statement. The completeness of this statement as a usable postulate for the further development of classical thermodynamics is briefly discussed.

Electron impact critical potentials are combined with thermochemical data to obtain values for the heats of the dissociationreactions, CH4=CH3+H, C2H6=C2H5+H, C2H6=2CH3, and nC4H10=2C2H5. The values found are: D(CH3–H)=101 kcal./mole, D(C2H5–H)=96 kcal./mole, D(CH3–CH3)=82.6 kcal./mole and D (C2H5–C2H5)=77.6 kcal./mole. These values are compared with estimates based on kinetic and photochemical data.

It is shown that a two‐particle force acting in coordinate space represents with a very good approximation the apparent coupling in space between two spinless atoms of ideal symmetrical or antisymmetrical assemblies at all temperatures higher than, or equal to, their transition temperature.

The photochemical efficiency, φ, for the decomposition of persulfate by light of λ254 mμ is determined by comparison with φ for the uranyl oxalate actinometer. The persulfate content was followed by the method of Kurtenacker and Kubina and in representative cases the hydrogen ion produced also was determined. The equation S2O8=+H2O+hv = 2HSO4−+O2/2 accounts quantitatively for the data. Evidence is given to show that the main reaction is not the decomposition of SO4−. Six tenths of a mole of persulfate is decomposed per Einstein absorbed by persulfate in dilute neutral and alkaline solutions when all oxidizable material is absent. Acetic acid increases this yield to unity but non‐oxidizable ions have a depressing effect. Many of the observations of Morgan and Crist also are verified. At constant ionic strength, φ remains nearly unchanged in alkali, but drops abruptly to less than 0.01 when solutions are acidified suggesting the formation of a weak acid containing photochemically inert persulfate. Absorption spectra and conductivity measurements, however, give no indication that such a weak acid is formed. The explanation offered for these facts is that the hydrogen ion associates with the thereby stabilizes the persulfate ion after the latter absorbs a photon. The stabilizing effects of other ions, except perhaps bisulfate, is much less than hydrogen which is thought to be related, among other things, to their larger size. Hydrogen peroxide was not found in any of the solutions.

The configurations of a binary mixture are described by specification of the occupants of a reference set of lattice point pairs, rather than by specification of the occupants of each individual lattice point. If the total interaction energy can be expressed as the sum of terms due to nearest neighbor pairs, the configurational partition function can be derived directly.